Lifting grapple

ABSTRACT

A lifting grapple composed of at least three fingers pivoted on a central pillar, each finger comprising at least two articulated phalanges. The fingers are arranged at 120* from each other on the central pillar which is connected to a lifting tackle. The motion of the phalanges is controlled by stretcher screws acting on ties connected to the phalanges. When the fingers are folded or retracted, the lower end of the central pillar is clear and a foot lever located on the lower end automatically controls the closing of the grapple when the foot lever comes into contact with a load to be lifted.

United States Patent [1 1 David et al.

[ Apr. 16, 1974 [73] Assignee: Etat Francais represents far le MinisterdEtat charge de la Defence Nationale-Delegation Ministerielte tamIArnement, Paris, France 22 Filed: Aug. 8, 1972 21 App1.No.:278,797

[52] US. Cl 294/88, 294/86 R, 294/106 [51] Int. Cl. B66c 3/16 [58] Fieldof Search, 294/1 R, 86R, 88, 106,

294/70, 69; 37/182, 183 R, 187, 188; 214/147 R, 147 G, 653, 654, 656

2,875,913 3/1959 Gohrke et al 214/654 3,268,092 8/1966 Hainer et a1.214/147 G X 3,441,155 4/1969 Norton 214/147 G X 3,589,766 6/1971Bormioli 294/106 Primary Examiner-Even C. Blunk AssistantExaminer-Johnny D. Cherry Attorney, Agent, or Firm-Eric H. Waters [5 7]ABSTRACT A lifting grapple composed of at least three fingers pivoted ona central pillar, each finger comprising at least two articulatedphalanges. The fingers are arranged at 120 from each other on thecentral pillar which is connected to a lifting tackle. The motion of thephalanges is controlled by stretcher screws acting on ties connected tothe phalanges. When the fingers are folded or retracted, the lower endof the central pillar is clear and a foot lever located on the lower endautomatically controls the closing of the grapple when the foot levercomes into contact with a load to be lifted.

6 Claims, 3 Drawing Figures LIFTING GRAPPLE FIELD OF INVENTION SUMMARYOF INVENTION A grapple provided in accordance with the invention isconstituted by three or more jointed fingers. Each finger is composed ofseveral parts called phalanges, numbering at least two, which arearticulated to each other.

Each phalange is rotatable. The rotation of each phalange is controlledby means of a hydraulic stretcher screw fitted with a pusher rod, suchstretcher screw being firmly connected to the phalange ahead of it.

The stretcher-screw pusher rods act on levers firmly connected to eachphalange and serving as supports to the stretcher screws. An oil feedfor each stretcher screw can be effected through channels hollowed outin the lever arms.

One result of the present invention is a wide-span grapple of largecapacity. For example, with a grapple each of whose fingers is composedof three phalanges each able to rotate 40, a total rotation of 120 isobtained for each finger.

One of the advantages of this grapple, as will be shown, lies in thefact that the fingers can be wholly retracted above the lower end of thepermanent support connecting the fingers to the lifting device. Thisallows the fingers to take up bulky loads while enclasping the same.

Another advantage lies in the fact that the length of thestretcher-screw piston rods is kept within a short limit due to thereduced displacement of each phalange.

Each stretcher screw can thus exert a considerable force independentlyof the effort of the other stretcher screws and such force is multipliedby virture of the lever arms on which the stretcher-screw thrust isexerted.

A further advantage, of great practical importance, is that thestretcher screws are fed without using any flexible piping, thusallowing the use of a working fluid at high pressure (500 bars, forexample).

The fingers of the grapple of the invention can exert considerableforces such as, for example, of the order of 160 kilonewtons, allowingthem to dig intocompact soils in the role of dredges or to restoreoff-centered loads back to the middle of the grapple.

Some examples of application of a grapple of the invention are thefitting of a dredge appliance attached rigidly to the end of a hydraulicgrab-bucket arm or the fitting of a lifting tackle for hoisting boatsout of the water.

The different characteristics and advantages of the invention will bebetter understood from the following description of a preferredembodiment given by way of non-limitative example and to be taken inconjunction with the attached drawings.

BRIEF DESCRIPTION OF DRAWINGS In the drawing:

FIG. 1 illustrates a vertical cross-sectional view of a portion of agrapple according to one embodiment of the invention;

grapples for lifting FIG. 2 is a horizontal cross-sectional view takenalong line llII of FIG. 1;

FIG. 3 illustrates a modification of a portion of the grapple of FIGS. 1and 2.

DETAILED DESCRIPTION FIG. 1 illustrates an upright pillar l of a grappleto be attached to a lifting tackle. Such pillar having vertical axis Z-Zis attached by an "articulated suspension around three trirectangularstuds, for example, to the end of a hydraulic grapple bucket for thepurpose of lifting boats out of the water in accordance with a devicewhich is the object of separate patent application, Ser. No. 278,798filed Aug. 8, 1972. This use is not, of course, exclusive and thegrapple accordance to the invention can serve also in various otherapplications.

The grapple illustrated is constituted of three jointed fingers atintervals of To simplify the drawing only one of the fingers, located onthe sectional plane, is completely illustrated the others being brokenaway.

Each finger is composed of three articulated phalanges 2, 3, and 4 andthree hydraulic stretcher screws 5,6 and 7.

The shell of stretcher screw 5 is connected firmly with pillar l. Theshell of stretcher screw 6 is carried by a pillar 8 connected firmlywith phalange 2 and the shell of stretcher screw 7 is carried by apillar 9 connected firmly with phalange 3.

Phalange 2 is pivoted about a stud 13 rotating within two casingscarried by pillar 1.. Phalange 3 is pivoted about a stud 14 rotatingwithin two casings 2a and 2b firmly connected with phalange 2. Phalange4 is articulated about a stud l5 rotating within two casings 3a and 3bfirmly connected with phalange 3.

The supports 8 and 9 are each formed of two arms respectively extendingfrom the casing 2a, 2b and 3a, 3b. Between the two arms of support 8 acylindrical tie 10 is placed which is acted upon by the pusher rod 5a ofthe stretcher screw 5. Similarly, between the two arms of support 9, acylindrical tie 11 is placed which is acted upon by the pusher rod 6a ofthe stretcher screw 6. Phalange 4 is also extended by a lever formed oftwo arms carrying a cylindrical tie 12 which is acted upon by the pusherrod 7a of the stretcher screw 7.

In the retracted position illustrated in FIG. 1, the ties l0, l1 and 12are slightly off center relative to the axis of pusher rods 5a, 6a and7a. The pusher rod sizes are such that each phalange can traverse a 40sector and, when the phalange is fully spread and the thrust is maximum,the ties l0, l1 and 12 are located in the extension of the pusher-rodstuds.

Phalange 4 constituting the free end of the finger shown in FIG. I has ashape equivalent to the use to which it is to be put such as, forexample, for gripping a sphere serving for boat raising. This shape can,of course, vary according to the particular uses intended. For example,phalange 4 can be pick-axe shaped in the case of a grapple intended toact as a dredge.

The stretcher screws'illustrated in FIG. 1 constitute single-actingtackle. The return of the phalanges into the retracted or foldedposition is effected by means of springs. Reference 16 indicates a bedhollowed into the body of pillar l for the return spring 16a for finger2. The return springs for fingers 3 and 4 do not appear in the drawing.

As a variant, stretcher screws 5, 6 and 7 can be double-acting tackle,with their piston rods (e.g., 5' in FIG.

3) articulated around associated studs (e.g., stud in FIG. 3) carried bypiston skirts (e.g. skirt 5a in FIG. 3). Also a rod can be used topivotably connect the skirts and studs.

The oil at very high pressure, of the order of 500 bars, reachesstretcher screw 5 through the rigid channel 17.

FIG. 2 illustrates in horizontal cross-section the various portions ofthe grapple.

This figure clearly shows the beds arranged at 120 intervals in pillar 1for receiving the three bolts 13. Also shown are the casings 2a, 2bextending from phalanx 2 and supporting stud 14, and the casings 3a, 3bextending from phalanx 3 and carrying stud 15.

The oil under pressure feeds through the rigid piping 18 into the stud13. It is distributed into a circumferential groove 19 from which ittravels into a channel 20 hollowed into the thickness of phalange 2.This channel extends into the thickness of the arm 8 (FIG. 1) and feedsthe stretcher screw 6.

Channel 20 communicates through a groove 21 with a channel 22 hollowedinto stud 14, which ends in a groove 23 from which the oil travels intochannel 24 extending into arm 9 (FIG. 1) thereby feeding stretcher screw7.

As shown in FIG. 1, whenin retracted position, the fingers are locatedwholly along a plane (which is actually a horizontal plane) passingthrough what is the lower end la of pillar 1. Thus, that end is clear inthe illustrated circumstances and the fingers are no impediment to anapproach to an object to be lifted.

This end la carries a foot pedal 25 which, when put into contact withthe load to be lifted, acts on a pusher rod 26. Said pusher rod opensanoil distributor 27 automatically governing the closure of the grapplearound the load-gripping mechanism.

The central pillar l is fitted by means of a taper bearing 28 into ahollow support 29 attached, for example, to the end of the hydraulicgrab-bucket arm. A hydraulic engine 30 is seated in support 29 to drivethe rotating grapple which allows the load to be slewed.

Each finger is independently fed with oil under pressure through anoleo-pneumatic accumulator 31 of about 10 liters capacity. The threeaccumulators are affixed to the periphery of the central pillar 1,between the fingers sites.

Clearly, without exceeding the scope of the invention, variousmodifications can now be foreseen by one skilled in the art, based onthe device described above by way of example.

What is claimed is:

l. A grapple comprising a central pillar and a plurality of extendibleand retractable fingers pivotably coupled to said central pillar, eachsaid finger including at least two pivotably connected phalanges, studspivotably supporting respective of the associated phalanges such thatthe phalanges extend in series one after the other from said centralpillar, the first stud in the series being supported in the centralpillar and the other of the studs being supported by respective of thephalanges, pressure responsive stretcher screws, one for each phalange,for controlling the positions of the phalanges, the pressure screwacting on the phalange supported on the central pillar being fast withsaid central pillar, each of the phalanges except the last in the seriesincluding a support on which is mounted the stretcher screw controllingthe next sequential phalange, each support including two parallel armsand a tie therebetween on which the action of the stretcher screwmanipulating the associated phalange is exerted, and pressure fluid feedmeans for the stretcher screws including channels in the studscommunicating through circumferential grooves provided in the studs withchannels provided within said arms supporting said screws.

2. A grapple as claimed in claim 1, wherein said central pillar has avertically disposed axis and wherein, when in retracted condition, thephalanges are located in extension of each other in a planeperpendicular to the vertical axis of the central pillar and are locatedwholly above the lower end of the said central pillar.

3. A grapple as claimed in claim 1, wherein the stretcher screws aresingle-acting and include sliding pusher rods acting against theassociated ties and comprising recall springs acting on the phalanges tourge the same to retracted position.

4. A grapple as claimed in claim 1, wherein the stretcher screws aredouble-acting and include pistons pivotably connected to the associatedties.

5. A grapple as claimed in claim 1, wherein each phalange except thelast in the series has the shape of :1 casing in which the studassociated with the following phalange rotates.

6. A grapple as claimed in claim 1 comprising a control foot lever and apusher rod and wherein the lower end of the central pillar carries saidcontrol foot lever, which when pushed against a load to be handled, actson said pusher rod for governing the fluid feed means.

I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,804,452 D t d April 16, 1974 Inventor) I Plerre Yvon Davld et 31,

It is ceftified that error appears in the above-identified patent andthat said Letters Patentarehereby corrected as shown below:

The assignee should reed Etet "Francais represente par le Ministred'Etat Charge de la Defense Nationale Dele gation Ministerielle pour" 1Armament, Paris France r Signed and sealed this 24thday of September1974.

(SEAL) Attest: V

McCOY M. GIBSON JR. I o. MARSHALL 'DANN Attesting Officer I Commissionerof Patents USCOMM-DC 60376-P69 us. sovnmuu'r PRINTING orrlcz u"O-liI-SJI.

F ORM PC4050 (10-69)

1. A grapple comprising a central pillar and a plurality of extendibleand retractable fingers pivotably coupled to said central pillar, eachsaid finger including at least two pivotably connected phalanges, studspivotably supporting respective of the associated phalanges such thatthe phalanges extend in series one after the other from said centralpillar, the first stud in the series being supported in the centralpillar and the other of the studs being supported by respective of thephalanges, pressure responsive stretcher screws, one for each phalange,for controlling the positions of the phalanges, the pressure screwacting on the phalange supported on the central pillar being fast withsaid central pillar, each of the phalanges except the last in the seriesincluding a support on which is mounted the stretcher screw controllingthe next sequential phalange, each support including two parallel armsand a tie therebetween on which the action of the stretcher screwmanipulating the associated phalange is exerted, and pressure fluid feedmeans for the stretcher screws including channels in the studscommunicating through circumferential grooves provided in the studs withchannels provided within said arms supporting said screws.
 2. A grappleas claimed in claim 1, wherein said central pillar has a verticallydisposed axis and wherein, when in retracted condition, the phalangesare located in extension of each other in a plane perpendicular to thevertical axis of the central pillar and are located wholly above thelower end of the said cEntral pillar.
 3. A grapple as claimed in claim1, wherein the stretcher screws are single-acting and include slidingpusher rods acting against the associated ties and comprising recallsprings acting on the phalanges to urge the same to retracted position.4. A grapple as claimed in claim 1, wherein the stretcher screws aredouble-acting and include pistons pivotably connected to the associatedties.
 5. A grapple as claimed in claim 1, wherein each phalange exceptthe last in the series has the shape of a casing in which the studassociated with the following phalange rotates.
 6. A grapple as claimedin claim 1 comprising a control foot lever and a pusher rod and whereinthe lower end of the central pillar carries said control foot lever,which when pushed against a load to be handled, acts on said pusher rodfor governing the fluid feed means.